Complex Numbers-Modulus and Argument

Let z = a + ib be any complex number , then |z| = √(a²+b²) is called the modulus of the complex number z and if (a,b) ≠ (0,0) , then θ = tan^-1(b/a) is called the argument or amplitude of z written as arg z. Argument of a complex number is not unique , since if θ be a value of the argument , so also is 2nπ + θ , where n ∊ I. 

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